JP3411697B2 - Ultrasonic detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to the presence or absence or position of an object.
The present invention relates to an ultrasonic detection device for detecting a position by an ultrasonic wave. [0002] 2. Description of the Related Art An ultrasonic detection device is generally a table such as a CRT.
Control the panel and detection operation placed over the display screen
An ultrasonic contact object made up of a control unit and transmitted to the panel
From the amount of ultrasonic absorption by the object to the position of the object (touch position)
Or to detect the presence or absence. [0003] Available ultrasonic waves propagate through solid surfaces.
Surface acoustic wave (SAW: Surface Acoustic)
ic Wave) and bulk acoustic waves (GA) propagating in solids
W: Guided Acoustic Wave
You. FIG. 19 is a schematic plan view of an ultrasonic panel.
The panel 1 is a liquid crystal panel or a CRT display.
Made of almost rectangular glass with the same curvature as play
And four low edges around the surface of panel 1
Plural reflective elements 2 printed with melting glass powder
Is formed. Reflection array 3
The rectangular portion surrounded by is the detection surface 6.
One end of two parallel opposing reflection arrays 3 sandwiching
Has a transmitter 4 for transmitting an ultrasonic wave and the other reflecting array 3
At one end receives an ultrasonic wave transmitted from the transmitter 4.
To form a set of detection pairs.
You. Detected by two sets of detection pairs perpendicular to each other on panel 1.
The position coordinates on the surface 6 are specified. Two sets of detection
The pair of reflection arrays 3 are arranged on the XY coordinate axes of the normal XY coordinate plane.
Reflection array of one set of detection pairs corresponding to each
If 3 is the X axis, the reflection array 3 of the other detection pair is Y
Corresponds to the axis. FIG. 20A shows a transmitter for surface acoustic waves.
The receiver 4 and the receiver.
The element 5 is composed of a pressure transmitting element 7 and a prism 8,
1 at the aforementioned position on the surface. Also in solid
4 and receiving of bulk acoustic wave (GAW) propagating through
The child 5 is attached to the end face of the panel 1 as shown in FIG.
Mounted directly. In the following description, we will refer to ultrasound
The surface acoustic wave shown in FIG.
You. Next, a method for detecting the coordinate position of an object on the panel surface is described.
The operation principle will be briefly described. As shown in FIG.
As shown, 5.5MHz transmitted shock wave from the control unit
When applied to the element 7, vibration occurs in the piezoelectric element 7 and
It is converted into a longitudinal wave in rhythm 8. Prism 8 and panel 1
At the interface of, the longitudinal wave is converted to a surface acoustic wave and
Of each reflection element of the reflection array 3
2 reflects a very small amount of energy at right angles. Reflection
The surface acoustic wave thus obtained is applied to the panel 1 as shown by the arrow in FIG.
Over the entire detection surface 6 and on the opposing reflective array 3
And reflected at right angles by the reflection array 3.
And received by the piezoelectric element 7 of the receiver 5. Receiver
5 receives the signal as shown in FIG.
The result is a signal with a long duration. In this case, detection of panel 1
When an object comes into contact with the surface 6 (touch occurs), the contact portion
The energy of the elastic wave is absorbed in minutes and is shown in FIG.
As the signal corresponding to the contact part is missing,
Appears as depression H. In this case, in FIG.
An elastic wave passing through the distance a, an elastic wave passing through the touch position b, or
In the case of an elastic wave passing through the longest distance c, it is difficult to reach the receiver 5.
Because there is a time difference, the first received elastic wave
Of the received elastic wave corresponding to the first position b and the longest distance c
Time T₁, T₀Is measured, the position of the object 9 (touch position)
Can be obtained. The received wave shown in FIG. 21 is applied to the receiving piezoelectric element.
Therefore, although it is converted to a voltage,
The time change of (width) is not uniform as shown in FIG.
Actually, as shown in FIG.
Become. The shape of this amplitude depends on the field between the prism 8 and the panel 1.
The surface, reflective element 2, panel surface, etc. are not necessarily uniform.
This is because surface acoustic waves do not propagate uniformly,
Rhythm 8, reflective element 2, and interface of panel 1 are determined by manufacturing
The whole is regarded as a unique shape (constant). On panel 1
Is touched with a finger or the like, as shown by the dotted line in FIG.
The surface acoustic wave corresponding to the touch position of
You. Touch from the position of the time axis of the dent due to this absorption
A coordinate component of the position is calculated. That is, two sets on panel 1
To transmit the transmitting shock wave alternately to the transmitter 4 of the detecting pair
From the position of the dent due to absorption on the X and Y coordinate axes,
The plane coordinate position of the touch position is calculated, and the touch position coordinates
Is detected. More specifically, first, a contact object is placed on the detection surface 6.
When there is no body (no touch), the voltage wave of FIG.
As shown by the circles in FIG.
High-speed sampling by the D converter
The streaming data is stored in the RAM. This stored data is
Sampling of surface acoustic waves received when not touched
This is ring data, and touch-on
It will be the baseline (standard). Next, at the time of normal detection, the received wave is similarly sampled.
And previously stored in RAM as a baseline
Data corresponding to the current sampling time
Differences subtracted from the current sampling data
To obtain measurement data at time t. This difference is
A value indicating the presence of absorption of ultrasonic waves due to contact with an object is shown.
After memorizing the baseline, if there is no object contact,
Measured sampling data remains unchanged and baseline
Is 0. FIG. 24 shows a case where a baseline is used as a reference.
Of the received voltage waveform that appears when you touch
The dent is indicated by a dotted line. Further, FIG.
Is to enlarge the dotted line indicating the touch in FIG.
This figure shows the difference between the digital value of the received voltage waveform
is there. In FIG. 25, at the time of each sampling shown on the time axis.
Between, ..., t_n-2, T_n-1, T_n, T_{n + 1}, T_{n + 2}, ...
Indicates that sampling was performed for same
In the figure, the difference ΔA of the sampling data_nIs the time
t = t_nIs the largest. Conventionally, the presence / absence of a touch and the touch coordinates are determined.
In other words, every time a transmitting shock wave is output from the transmitter 4,
The maximum difference ΔA_nAnd compare it with the reference level value Ath
do it, ΔA_n≦ Ath: No touch, ΔA_n> Ath ... with touch, And if there is a touch, ΔA_nTime t corresponding to_n
The coordinate component obtained from is the touch position coordinate on panel 1.
Touch position from the coordinate components of the X and Y coordinate axes
Has been detected. By the way, as a touch sensor, an ultrasonic detection method is used.
The problem with using a discharge device is that it is waterproof and drip-proof.
Structure. Generally, in an ultrasonic detection device, waterproofing is performed.
Therefore, the glass surface forming the detection surface 6 of the detection panel 1
If you stick things together, they will absorb or miss sound waves
Then, as shown in FIG.
A liquid crystal display attached and fixed to the liquid crystal display unit body A
It is difficult to make I-B completely waterproof and drip-proof.
In particular, sound energy is concentrated near the glass surface
For touch sensors using surface acoustic waves,
Even with the close contact structure, the sound absorption is high,
Drip proof has a fundamental difficulty. On the other hand, the method of bulk acoustic wave
Then, the degree of sound absorption is greater for surface acoustic waves.
Since it is not, some degree of waterproofing and drip-proofing is possible. FIG. 27 is a diagram showing the relationship between the volume elastic wave method and the volume elastic wave method.
Outer peripheral surface of glass detection panel 1 by surface tape 101
Part and the bezel 10 are adhered to the outer peripheral surface of the detection panel 1.
On the end face of the reflection array 3 attached and the detection panel 1
Bezel 10 including transmitter 4 and receiver 5 provided
Waterproof and drip-proof structure of the area covered by
is there. FIG. 28 shows the outside of the bezel 10 and the detection panel 1.
An O-ring 102 is interposed between the peripheral panel and the detection panel.
Apply pressure between the bezel 1 and the bezel 10 to form a close contact structure
This achieves waterproofing and drip-proofing. [0014] [Problems to be solved by the invention]Problem A In ultrasonic detection devices, transducers are generally
LiNbO used as_ThreeSingle crystals and piezoelectric ceramics
Large change in characteristics due to temperature. In addition, electronic circuit components and security
In addition to the change in the temperature characteristics of the sensor plate, the base shown in FIG.
The line itself had a large temperature drift. this
Due to temperature drift, for example, ultrasonic detection devices and
After turning on the computer for a while, the actual
Of the touch line as a result of the
Incorrect operation may result. To address this issue
Conventionally, regularly refresh the baseline
That work was being done. Refresh is, for example,
A / D that becomes a baseline with a cycle of 30 seconds or 1 minute, etc.
That is, the conversion value is replaced with the latest A / D conversion value.
However, in this method, when a finger touches
When the refresh is performed, the touched sampling data
Data is stored as baseline data.
Until the next refresh is performed without touching
Says that the touch of the part touched before cannot be determined
This causes inconvenience. Also, when the ambient temperature changes drastically,
Between the current refresh and the next refresh
The effect of temperature changes on the
Malfunction occurs because the slope data does not follow the temperature change.
It will be easy to produce. Also, a circuit of a control unit of the ultrasonic detection device
From the power supply circuit, host computer or electromagnetic waves
Susceptible to noise. This is for sampling
The A / D converter used operates at high speed, and
The internal impedance of the element 7 is high and picks up external noise
Because it is easy. For example, as shown in FIG.
Error E due to noise in the converted sampling data
Superimposed, and if normal, the maximum difference from the baseline
P and Q points with noise superimposed on the R points detected
Is large and detected as the maximum value.
The switch position is the correct sampling time tn corresponding to the point R.
Erroneous sun corresponding to P point or Q point without being calculated from
Pulling time t_PAnd t_QFrom the touch position
Is erroneously detected by noise. Also in FIG.
As shown, the reference value for touch detection is actually exceeded
There is no noise like point B, but there is no reference
Exceeding the value Ath or fluctuating finger pressure
False detection and touch / no touch
Such a malfunction may occur. It is an object of the present invention to provide a method for controlling the temperature of a baseline and the like.
Ultrasonic detection device that can automatically correct the effects of fluctuations due to
Is to provide an installation. The object of the present invention is to
Ultrasonic detection that prevents erroneous detection due to air noise
It is to provide a device. [0017]Problem B Ultrasonic detection of conventional method of transmitting ultrasonic waves of the same wavelength
The device has the following disadvantages. That is, this species
In the ultrasonic detection device of (1), the detected coordinates (X
To increase the resolution of the target, the Y coordinate), the receiver 5
A / D converter for A / D converting received ultrasonic signals
It is necessary to increase the sampling speed. For example, Gala
When the speed of the sound wave on the surface is about 3000 m / sec, the coordinates
Sampling rate to 0.3 mm resolution
Is ## EQU1 ## 0.3 mm / 3 × 10⁶(Mm / sec) =
0.1 / 10⁶(Sec) = 0.1 μsec Therefore, the sampling frequency is 1 / (0.1 μsec
c) = 10 MHz is required. This is the A / D conversion
Since the speed is quite fast as a converter, the A / D converter
The used IC becomes expensive and the cost of the whole circuit increases.
Cause. Also, before the A / D conversion, the ultrasonic AM detection is performed.
Wave (AM demodulation), but used for detection
The frequency of the sound wave is about 5 MHz.
It is difficult to completely remove the ripple
Ripple when performing high-speed sampling at frequencies higher than
Is a big problem. Faster sampling speed
Control the timing from the microprocessor to respond
Difficult to do, fast timing generation in hardware
And control circuitry, which is expensive.
There is a problem that is worthwhile. In addition, a high-speed control circuit is realized.
Control circuit becomes a high current consumption type,
Easy and temperature drift of baseline data
It is necessary to use a low current consumption circuit because
Is difficult. To increase the resolution of the touch coordinates, the data
It is necessary to increase the sampling speed. Speed of sound wave propagation
Since the degree is constant, doubling the sampling rate
The resolution is doubled. However, the sampling speed was increased
The number of data points sampled in proportion to
Data processing time. Also, Sampling
A faster and more expensive A / D conversion
Number of data points that need to be changed or stored in SRAM
, The memory size of the SRAM should not be increased.
And cause prices to rise. Another object of the present invention is to provide a high-speed A / D converter.
To provide a high-resolution ultrasonic detection device without performing
It is. [0021]Problem C Conventionally, the processing of sampled data is as follows.
There was a problem. As shown in FIG.
Panel 1 having a 300 mm × 200 mm detection surface 6
Will be described as an example. The speed of sound wave propagating in glass is 300
Assuming 0 m / s, as shown in FIG.
Of the longest path of the sound wave output from
Is an approximation, ## EQU2 ## 300 × 2 + 200 = 800 (mm) Becomes The transit time of the sound wave passing through this path is ## EQU3 ## 800 (mm) / 3000 (m / s) = 0.2
7 (ms) Becomes That is, it emits shock waves and samples data
Is 0.27 ms until is completed. Similarly, the Y axis
Data sampling of the sound wave output from the transmitter 4 is completed.
The time to complete ## EQU4 ## (300 + 200 × 2) (mm) / 3000
(M / s) = 0.23 (ms) Becomes Therefore, the data sample is taken along the X-axis and Y-axis.
The time required for ## EQU5 ## 0.27 + 0.23 = 0.5 (ms) It is. Thus, in the ultrasonic detection device, the sampler
Since the sampling speed is fast, from the transmission of sound waves to the end of sampling
Is completed in a short time. The data sampling rate is, for example, 5 MHz.
z, one sampling time 1 / (5 × 10⁶)
The distance of the sound wave traveling to (s) is (Equation 6) 3 × 10⁶(Mm / s) · 1 / (5 × 10⁶)
(S) = 0.6 (mm) Therefore, considering the reciprocation of the sound wave, the resolution of the detected coordinates
Is 0.6 (mm) /2=0.3 (mm). Sun
For the number of pulls, the resolution is 0.3 mm (5 MHz sample).
Ring), the number of samples on the X axis is (Equation 7) 300 (mm) / (0.3 (mm)) = 1000 points The number of samples on the Y axis is (Equation 8) 200 (mm) / (0.3 (mm)) = 667 points Becomes Increasing the resolution increases the number of samples
You. The total sampling time for the X and Y axes is short
However, due to the large number of sampling data points,
Processing time is longer. Touch this data processing time
This caused the overall detection speed to slow down. For example, data processing is commonly used.
When processed by an 8-bit microprocessor
Processing time is about 20 ms for X and Y coordinates.
I do. During this processing time, it takes
Time and other processing time (for example,
Conversion time to ASCII code for communication to data)
It takes about 3ms for scanning, and therefore, at the time of full scanning required for detection
It takes about 23 ms for the interval. In addition,
Temperature drift and noise
About 10 to 20 m
s processing time is added, the total scanning time is about 33 to
Reaches 43ms. At this scanning speed, in a normal touch operation,
Although this is of little concern in time, for example, using a pen
Pen computing and finger signing
Touch operation is quite fast and data processing is
Cannot be accurately followed. Pencon
For tablets used for computing, touch
The sampling speed of the target is about 5 ms. Then,
Ultrasonic touch panels are used for
When using, adjust the scanning time to the sampling speed.
Needs to be about 5 ms. An object of the present invention is to provide an ultra-high-speed scanning
An object of the present invention is to provide a sound wave type detection device. [0026] [0027] [0028] [0029] [Means for Solving the Problems] To solve the problem B, the ultrasonic wave of the present invention
The type detection device transmits a plurality of ultrasonic waves of different wavelengths to the panel X
Means for oscillating in the direction and the Y direction, and the transmitting means
Time-division transmission of different ultrasonic wavelengths transmitted from
Control means for performing control for the transmitted supersonic
Receiving means for receiving a wave, and the transmitted ultrasonic wave propagates
A predetermined corresponding to each of the plurality of different wavelengths
At predetermined intervals and passing through a detection surface on the panel
An ultrasonic wave having a wavelength is selected and reflected, and transmitted to the receiving means.
A reflection array pair to be carried, and
By comparing the ultrasound of a given wavelength with the reference level
Touch of the object at the reflection position of the given wavelength
Means for detecting the presence or absence. [0031] [0032] [0033] [Action] In order to solve the problem B, the present invention
Oscillates ultrasonic waves of different wavelengths, and for each different wavelength of ultrasonic waves
Ultrasound waves can be detected on the panel differently by different reflective array pairs.
The light is propagated to the receiving means through the exit surface position. Different of ultrasonic
Corresponding to different detection positions on the detection surface.
Of the corresponding detection position from the ultrasonic wave of
Because it judges nothing, it is high regardless of the sampling speed
Achieve resolution. In order to solve the problem C, the present invention
The presence or absence of an object touch from the sampled data
Sampling touch when an object touch is detected
Data processing is performed on the sampler near the touch detected.
Processing is limited to the sampling data.
The processing time is reduced, and the scanning time can be shortened.
In addition, the present invention provides hardware for the subtraction means and the comparison means.
The air configuration makes it possible to quickly determine the presence or absence of a touch.
Therefore, the scanning time can be shortened. [0036] [0037] 【Example】Example A One embodiment of the ultrasonic detection device of the present invention for solving the problem A
Will be described with reference to FIG. Figure 1
And the ultrasonic shock wave output from the shock wave generator 11
Is an X-axis switch 13 and a Y-axis switch via a transmission amplifier 12.
The switch 14 is provided. X-axis switch 13 and Y
The shock wave output from the shaft switch 14 is shown in FIG.
X-axis transmission corresponding to transmitter 4 provided on panel 1
The input is made in correspondence with the slave 4a and the Y-axis oscillator 4b, respectively.
You. Super output from X-axis transmitter 4a and Y-axis transmitter 4b
The sound wave is generated by using the surface of the panel as a surface acoustic wave.
And propagating in the Y-axis direction, and is provided with the panel 1 shown in FIG.
X-axis receiver 5a and Y-axis corresponding to the obtained receiver 5
Each is received by the receiver 5b. X axis receiver 5
a and surface acoustic waves received by Y-axis receiver 5b
Are converted into ultrasonic electric signals and the corresponding X-axis
The switch 15 and the Y-axis switch 16
The ultrasonic signals transmitted through the switches 15 and 16 are transmitted to the receiving amplifier 17.
Is entered. X-axis switches 13, 15 and Y-axis switch
Switches 14 and 16 are controlled by a microprocessor 26.
X-axis switches 13 and 15 or Y-axis switch 1
One of 4 and 16 is turned on and the other is turned off
Is controlled. Ultrasonic wave amplified by the receiving amplifier 17
The signal is sent to a demodulator 18 where the ultrasonic signal is
(Amplitude modulation) is detected and converted into a DC component. Demodulator
The output of 18 is an A / D (analog / digital) converter 19
Sampling at high speed as time passes here
Is Sampling data from A / D converter 19
Is an SRAM (static run) via the buffer 20.
(Dumb access memory) 21 for storage.
The CPU 23 of the microprocessor 26 is an A / D converter
When the sampling operation of No. 19 is completed, the
The stored sampling data is written via the buffer 22.
Get in. The CPU 23 stores the data stored in the SRAM 21
Digital filtering at regular intervals
And automatically corrects the data.
Stored in the SRAM 21 as baseline data,
An object is displayed on panel 1 based on this baseline data.
Calculation of whether there is a touch
Perform the calculation to find the coordinates. The CPU 23 has a buffer 20,
22 to control the direction of data flow. micro
In addition to the CPU 23, the processor 26
RAM 24 used for the storage of the
A ROM 25 for storing is provided. CPU 23
Touch-on / touch-off and touch determined accordingly
The position coordinate data is transferred to the host
Sent to the computer 28. Next, the presence or absence of touch-on of the object according to the present invention
The operation of detecting the position coordinates will be briefly described. Ma
Prior to the detection operation,
Shock waves are output respectively, and the X-axis and Y-axis
The corresponding ultrasonic sampling data is digitally filtered.
Baseline data that can be
Stored in the SRAM 21. X axis switch
Switches 13 and 15 are on (Y-axis switches 14 and 16 are off)
F), the detection operation for the X axis is performed. Immediately
The shock wave is intermittently output from the shock wave generator 11,
Via the A / D converter 19 of the ultrasonic electric signal based on the shock wave
The sampled data is used as measurement data in SRAM2
1 is stored. Also, the presence / absence of touch-on in the RAM 24
The reference level value, which is the reference for determining
Each is set for. CPU 23 is ROM2
5 Check the measurement data according to the calculation program stored in
Perform an outgoing operation. FIG. 2 is a flowchart showing the detection operation of the present invention.
The ultrasonic electric signal is generated in step S1.
Sampling time (below, referred to as “reception time”)
And the sampling time of the end of reception (hereinafter referred to as the start value).
Is read from the SRAM 21
It is stored in a register of the CPU 23. In step S2
And the reference level relating to the X axis stored in the RAM 24
The value is written to the CPU 23. Next, proceed to step S3.
Measurement with the baseline data stored in the SRAM 21.
The constant sampling data is read by the CPU 23 and
Measurement sampling corresponding to each sampling time
Data of difference between data and baseline data is calculated
Then, it is stored in the register of the CPU 23. Next,
The process moves to step S4, and as shown in FIG.
The reference for which the maximum difference data was obtained and stored in the register
It is determined whether the level exceeds the level Ath. Reference level
If it exceeds, the sampling time is X_MIt is said that
The data is stored in the register, and the process proceeds to the next step S5. Y axis switch
Switches 14 and 16 on and the same for the Y axis
Steps S1 to S4 are executed for the ultrasonic wave of the Y axis.
Even if the maximum difference data exceeds the Y-axis reference level value
If it is determined that there is an object touch on panel 1
(Touch-on) is determined, and the routine goes to Step S6. Stay
In step S6, the sampling time X_MX corresponding to
The position of the axis is specified as the X coordinate of touch-on,
The Y coordinate is also specified. In step S7, the CPU 23
Is a data indicating touch-on to the host computer 28.
Data with the coordinate data. In step S4, based on the maximum difference data,
No touch-on if the sub-level value is not exceeded
And without moving to step S5,
And the detection operation of the next measurement sampling data is repeated.
It is. Also, in step S5, the maximum
If the difference data does not exceed the reference level value,
Move to step S6 assuming that thion was not detected.
The detection operation is repeated immediately. Before the above detection operation is performed,
Real-time sampling at regular intervals
The line data is updated. Here, applied to the present invention
Brief explanation of the principles of digital filtering
I will tell. To eliminate baseline data drift
Newly measured sampling data in real time
Use filtered values. Generally, analog times
On the road, give a step unit signal 1 to the primary delay element
Response t after t seconds is (Equation 9)     f = 1−exp (−t / τ) (1) Given by Response f when t = nΔt_n, T =
Response f at (n + 1) Δt_{n + 1}Where Δt is the time constant
Approximately if it is small enough for τ, (Equation 10)     f_{n + 1}= F_n+ (Δt / τ) (1-f_n) (2) Holds. Here, if τ = p · Δt, [Equation 11]     f_{n + 1}= F_n+ 1 / p · (1-f_n(3) Becomes Applying equation (3) to digital filtering,
Since the input signal is not always a step signal, g_{n + 1}age,
Filtered value f at t = (n + 1) Δt_{n + 1}
Is the filtered value f at t = nΔt_nAnd t
= Input value g at (n + 1) Δt_{n + 1}From the following equation, (Equation 12)     f_{n + 1}= F_n+ 1 / p · (g_{n + 1}−f_n) (4) Required by In the present invention, the CPU 23
At stored previously filtered t = nΔt
Baseline data f_nA / D converted this time
Measurement sampling data g at t = (n + 1) Δt
_{n + 1}And the digital filtering
Sline data f_{n + 1}Is calculated by equation (4). here
Where p = τ from the sampling interval Δt and the time constant τ.
/ Δt. For example, between sampling
Interval Δt = 30 msec, time constant τ = 30 sec
And 1 / p = Δt / τ = 1/1000. Each sump
For each data corresponding to the ring time (corresponding to the coordinates)
Performs a digital filtering operation according to equation (4).
Update the baseline data and update the updated sample
Replace the baseline data with the previous baseline data.
After updating the baseline data, the detection operation is
This is performed based on the sine data. This digital file
Does filtering reduce the effects of fluctuations?
If noise is added to the measured sampling data,
Digital drift even when drift due to temperature occurs.
Filtered baseline data accounts for these effects.
I do not receive. Also, when touching the panel, the time constant
For a touch time within a certain delay time determined by τ
Does not affect baseline data. However, the touch on the panel continues for a long time.
The digital sampling from the measured sampling data.
Influence of touch on filtered baseline data
Appears, and the error increases. This problem
To resolve, touch off after touch is detected
Until is detected, the baseline near the touch position is
Digital filtering of data
Configure not to update only part of the data (program
). Next, correction of the above-mentioned baseline data and
Separately, noise is added to the measurement sampling data and malfunctions occur.
If so, noise from the measurement sampling data itself
Need to be removed. The present invention solves this problem.
The embodiment will be described with reference to the flowchart of FIG.
I do. In step S11 shown in FIG.
Sample for starting reception of measured sampling data
Sampling time (hereinafter referred to as start value) and reception end sump
Whether the ring time (hereinafter referred to as an end value) is the SRAM 21
And stored in the register of the CPU 23. S
X axis stored in RAM 24 in step S12
Is written into the CPU 23. next
Move on to step 13, the base stored in the SRAM 21
Line sampling data and measurement sampling data
Is read out by the CPU 23, and at each sampling time,
Measured sampling data and baseline corresponding to each
The data of the difference from the data is calculated and the
Is stored in the data. Next, the process proceeds to step S14, where the CPU 23
n-th smoothed difference data ΔH_nTo seek
For example, n-2, n-1, n,
n + 1, n + 2nd difference data ΔA_n-2, ΔA_n-1, Δ
A_n, ΔA_{n + 1}, ΔA_{n + 2}Is read and the smoothing equation (5) (Equation 13)            ΔH_n= (1/8) (ΔA_n-2+ 2ΔA_n-1                                     + 2ΔA_n+ 2ΔA_{n + 1}+ ΔA_{n + 2}) (5) The difference data ΔH smoothed according to_nCalculate the cash register
Memorize in the star. Hereinafter, the detection operation is performed by the smoothing process.
Difference data ΔH_nIt is performed based on. Next, the operation proceeds to step S15, where
In this way, the maximum difference data among the difference data
Whether the reference level Ath stored in the register is exceeded
Judge. If the reference level is exceeded, the sample
Time X_MIs stored in the register and the next step S1
Move to 6. Switch the Y-axis switches 14 and 16 on
Steps S11 to S15 are similarly executed for the Y axis.
The maximum difference data for the ultrasonic wave on the Y axis is
If it is determined that the reference level value exceeds
Is determined to have touched an object (touch-on)
It moves to step S17. In step S17, the sump
Ring time X_MThe X-axis position corresponding to
The coordinate is specified, and the Y coordinate is specified similarly. Stay
In step S18, the CPU 23
The data indicating the touch-on for No. 8 and its coordinate data
Send together. In step S15, the maximum difference data is
No touch-on if the reference level is not exceeded
And without moving to step S16, the X-axis
The next measurement sampling data detection operation repeats at
returned. Also, in step S16, the Y-axis
If the maximum difference data of the
It is determined that no touch-on has been detected in step S17.
The detection operation is repeated without moving to step (1). The smoothing equation in step S14 is the above Δ
H_nIn addition to the following formula, [Equation 14]     ΔH_n= (1/3) (ΔA_n-1+ ΔA_n+ ΔA_{n + 1}) (6) (Equation 15)     ΔH_n= (１ ／) (ΔA_n-1+ 2ΔA_n+ ΔA_{n + 1}) (7) (Equation 16)     ΔH_n= (1/5) (ΔA_n-2+ ΔA_n-1                         + ΔA_n+ ΔA_{n + 1}+ ΔA_{n + 2}) (8) May be used. The smoothing equation is weighted as in equations (5) and (7).
You may also do the finding. Any degree of weighting
Is ΔA_nThe larger the weight for_nValue and smoothing
The data is close. In addition, sampling data for smoothing
The data is not limited to three points as shown in equations (6) and (7),
May be smoothed. In the smoothing expression,
For places, the dividing value is 2^N(N is an integer)
Then, in arithmetic processing, division can be achieved only by shifting bits.
As a result, high-speed operation is possible. For example, (5)
Using the formula, the number to divide is 8 = 2^ThreeTherefore, the 3-bit
Division is realized only by bit shift. As described above, the measurement sampling data
Perform a smoothing process every time for all points
The ring data itself is smoothed, causing malfunctions due to noise.
Life can be prevented. However, all measurement sump
Smoothing ring data takes a long time to calculate
There is a possibility that the operation speed is reduced. At this time, first smooth
Difference data ΔA_nUsing touch or not
Only when it is determined that there is a touch,
Smoothing processing is performed only on the difference data near the touch position.
The touch position can be detected faster and more accurately.
You. Equation (4) is applied to the measured sampling data.
Perform digital filtering using the baseline
The data is corrected at regular intervals, and the smoothing
Can be used to smooth the measured sampling data sequentially.
it can. Corrected baseline data and smoothed
If the detection operation is performed using the measurement sampling data,
Malfunctions due to drift and noise can be reliably prevented
You. [0052]Example B An embodiment of the present invention for solving the problem B will be described.
I do. FIG. 4A shows a panel 3 for constituting the present invention.
1 is one embodiment. One corner of this panel 31 is in the X direction
A transmitter 32 for generating an elastic wave is provided.
In the corner and the diagonal corner, the X direction transmitted from the transmitter 32
A receiver 33 for receiving the elastic wave of
You. Similarly, at one corner, an elastic wave in the Y direction is generated.
A transmitter 34 is provided at the one corner and a diagonal corner.
For receiving the elastic wave in the Y direction transmitted from the transmitter 34
Receiver 35 is provided. Of the surface of the panel 31
A reflection array composed of a plurality of reflection elements 2 at four peripheral portions
36 are formed. In the periphery in one X direction
And the distance (pitch) between one adjacent reflective element 2 and 2
Is different from the interval between the other adjacent reflection elements 2 and 2.
You. And a reflective element in the other peripheral portion in the X direction.
The interval between 2 and 2 is opposite to each other in the peripheral portion in one X direction.
Are arranged at equal intervals between the reflecting elements 2 and 2 in the X direction.
A reflective array pair is formed. This reflective array pair
Reflection array pair to which the elastic wave transmitted from Nobiko 32 corresponds
Propagating at right angles on the detection surface of panel 31
At an angle received by the receiver 33.
The peripheral portion of the panel 31 in the Y direction is also the peripheral portion of the panel 31 in the X direction.
And a reflection array pair arranged in the same manner as in FIG. X
In the case of the direction and the case of the Y direction, the operation is exactly the same.
Hereinafter, only the case in the X direction will be described. For example, the output from the transmitter 32 in the X direction is
The ultrasonic waves propagate as shown in FIG. Ultrasound
The reflector at point A where the spacing between the daughters matches the wavelength of the ultrasonic wave being propagated
Point B of the reflection array pair shown in FIG.
To change the course in the direction of the receiver 33. Reflection at point B
The distance between the elements 2 is equal to the distance between the reflective elements 2 at point A.
Is configured to be equal to the wavelength of the sound wave
No. Therefore, the sound wave reflected at point A is reflected again at point B.
Then, the course changes again in the X-axis direction as shown in FIG.
Further, it is received by the receiver 33 in the X direction in FIG.
The sound wave reflected at point A in FIG. 4A is actually only point A
The sound wave propagation area in FIG.
It is distributed over the width of S. Such reflections are made
The reason for this is that the reflection element operates at a frequency called the grating.
Is configured as a selective elastic wave reflector
It is. That is, the interval between the reflection elements is half the wavelength of the elastic wave.
At frequencies that are integral multiples of
Because they are added in phase, the strength known as Bragg reflection is
Utilizing a well-known phenomenon in which reflection occurs. FIG. 4B shows the left side of the detection surface in the X direction.
X is the end coordinate_L, The rightmost coordinate is X_RAnd at each coordinate
Is the distance (pitch) between the reflection elements_XL, Λ_XRAnd
The distance between the X coordinate on the X direction detection surface and the reflection element is
It is a figure showing roughly the relation of cloth. Reflective element pitch
The cloth does not necessarily have a linear relationship with the element position X as shown in the figure.
No need to be. In FIG. 4B, from the transmitter 32
The wavelength λ emitted for the X coordinate is [Equation 17]     λ = (λ_XR−λ_XL) / (X_R-X_L) ・ (XX)_L) + Λ_XL           = AX + b (9) Represented by For example, generate sound wave of λ = 0.6mm
To make it sound, the sound speed on the glass is about 3000 m / sec.
Then, f = 3000 (m / sec) /0.6 (mm)
= 5MHz vibration must be generated by the transmitter 32
You. Here, from the transmitter 32 in the X direction, the wavelength λ = λ_XL~
λ_XRIs transmitted and received by the receiver 33.
Then, when the received sound wave intensity with respect to the wavelength λ is measured, for example,
As shown in FIG. In the same figure, the solid line
When the received sound intensity distribution is not
Become. When you touch with your finger,
Wavelength equal to the reflective element corresponding to the touched X coordinate position
λ = λ_XSound waves are absorbed by the finger and fall below the baseline
You. To be precise, the wave at the point that is the lowest from the baseline
Length is λ_XIt is good. In equation (9), λ = λ_XSubstitute
If (Equation 18)                    X = (λ_X−b) / a (10) Thus, the touched X coordinate position is calculated. FIG. 6 is a circuit diagram for solving the problem B.
FIG. 2 is a schematic diagram, and the same parts as those in FIG.
Omitted. In FIG. 6, the microprocessor 26 is
Different digital values that increase at a fixed rate are sequentially time-divided,
Output to the D / A converter 41. D / A converter 41 is input
Digital values to be sequentially converted to the corresponding analog voltage values
And applies the voltage value v to the voltage controlled oscillator (VCO) 42
I do. The voltage control transmitter 42 outputs a signal corresponding to the voltage value v.
Shock waves, which are sine waves of a given frequency, are sequentially output. Electric
A so-called V / F converter instead of the pressure control transmitter 42
(Voltage-frequency converter) may be used. The impulse output from the voltage control transmitter 42
The strike wave is transmitted via the transmission amplifier 12 to the X-axis switch 13 and
Through the X-axis switch 13
The signal is sent to the oscillator 32 and through the Y-axis switch 14.
The transmitted signals are supplied to the transmitters 34, respectively. further
The shock wave is also applied to the waveform shaper 43, where the sine
The wave is shaped into a rectangular wave and output to the counter 44. Mosquito
The counter 44 counts the shaped rectangular pulses,
The counted value is output to the microprocessor 26. wave
The shape shaper 43 does not have to be particularly provided. Counter 44
By using, the input voltage v to the voltage controlled oscillator 42
And the output frequency f, and the voltage v
Is applied to the voltage control transmitter 42 in real time.
To obtain the frequency f. The oscillators 32 and 34 are driven at the frequency f.
And λ = c / f (where c is a sensor plate, for example, glass
An ultrasonic wave having a wavelength λ of the sound speed of the ultrasonic wave is generated. This ultrasonic
Is received by the receiver 33 or 35 as described above.
X-axis switch 15 or Y-axis switch 16
Amplifier 17, demodulator 18, and A / D converter 19, respectively.
Is supplied to the microprocessor 26 and the sampling data
The data is saved in the RAM 24 as data. RAM 24 is
If the number of data to be stored is large, the microprocessor 26
May be provided outside of the device. The microprocessor 26 is a D / A converter
41 to control the input voltage v to the voltage control transmitter 42
Change the frequency of the ultrasonic wave (and thus the wavelength λ) step by step
Sampling data when not touching as shown in 5
Data is obtained first, and RAM2 is used as baseline data.
4 is stored. At this time, the counter 44 is deactivated for a predetermined time T.
Calculates the frequency f = K / T from the count value K sent sequentially for each
Then, the wavelength is obtained by the equation λ = c / f.
The coordinates are calculated according to 0) and sequentially stored in the RAM 25.
As a result, the baseline data and the coordinates correspond
become. The same frequency from which the baseline data was found
Obtain measurement sampling data in the (wavelength) range, and
Calculation of whether or not there is a touch of an object on
An operation for obtaining coordinates of the touch position is performed. Voltage controlled transmitter
A shock wave is output in stages from 42,
Sampling of sonic electric signal through A / D converter 19
The data is R as measurement data corresponding to the frequency (wavelength).
Stored in AM24. The RAM 24 has a touch-on
The reference level value, which is used as a criterion for determining the presence or absence of
And Y axis. CPU 23
Measurement data is stored in accordance with the calculation program stored in the ROM 25.
Data detection operation. FIG. 7 is a flowchart showing the detection operation of the present invention.
In step S31, the ultrasonic electric signal
Sampling time (below)
Below, referred to as the start value) and the sampling time at the end of reception
(Hereinafter referred to as an end value) is read from the RAM 24.
And stored in the register of the CPU 23. Step S32
The reference level for the X axis stored in the RAM 24
The bell value is written to the CPU 23. Next, step S3
3 to the baseline sample stored in the RAM 24.
Pulling data and measurement sampling data are stored in CPU2.
3 for each frequency (wavelength)
Between measured sampling data and baseline data
The difference data is calculated and stored in the register of the CPU 23.
It is. Next, the process proceeds to step S34, as shown in FIG.
Next, the maximum difference data of the difference data is obtained and
The reference level Ath stored in the
Refuse. If the reference level is exceeded, the frequency (wave
Length) is λ_XIs stored in the register and the next step
Move to S35. Switch Y-axis switches 14 and 16 on
Steps S31 to S34 are similarly performed for the Y axis.
The maximum difference data is also obtained for the ultrasonic wave on the Y axis.
If it is determined that the value exceeds the reference level value of the Y axis,
Panel 1 is judged to have touched an object (touch-on)
To step S36. In step S36, the
Sampling frequency (wavelength) λ_XThe position of the X axis corresponding to
It is specified as the touch-on X coordinate, and the Y coordinate is
Is determined. In step S37, the CPU 23
Data indicating touch-on is sent to the computer 28.
Is sent out together with the coordinate data. In step S34
If the maximum difference data does not exceed the reference level value
It is determined that there was no touch-on, and the process proceeds to step S35.
The next measurement sampling data on the X-axis without
Is detected repeatedly. Also, in step S35
And the maximum difference data for the Y axis exceeds the reference level value
If no touch-on is detected
The detection operation is repeated without moving to step S36.
You. The received ultrasonic intensity distribution shown in FIG.
As shown in FIG. 8, the A / D converter 19 is discretely arranged at regular intervals.
Determined by sampling. This sample
The speed of D / A is time-divisionally
Voltage applied to voltage control transmitter 42 via converter 41
Because it is related to v, it is free without being directly affected by the speed of sound
Can be adjusted. Therefore, the A / D converter 19
Need not be particularly fast. Measuring sump
The resolution of the ring data is in principle the voltage control transmitter 42
The resolution of the applied voltage v, and hence the D / A converter 41
Determined by ability. In addition, one point sampling
Since the time can be extended if necessary, the demodulator 18
AM detection performed in
The AM detection output (and thus the A / D conversion).
Ripple can be sufficiently removed and high accuracy
Can be measured. Further, increasing the sampling speed
Curve interpolation to improve touch detection resolution
It is conceivable to use the law. This method is actually
Optimal touch position data between sampled points
Is calculated based on actual sampling values in the vicinity.
It is. There are various interpolation methods, for example, polynomial
, Cubic interpolation, cubic interpolation, etc.
There is. Here, as an example, the case of using the quadratic interpolation method
Will be described. In FIG. 9, ΔA_n-1, ΔA_n, Δ
A_{n + 1}, ΔA_{n + 2}Is t = t_n-1, T_n, T_{n + 1}, T_{n + 2}time
A / D conversion values sampled at points (baseline or
Difference). Sampling is performed at regular intervals
Therefore, the interval is defined as h, and D_n-1, D_n,
D_{n + 1}, K, k₁Defines [Equation 19] D_n-1= ΔA_n-ΔA_n-1 D_n = ΔA_{n + 1}-ΔA_n D_{n + 2}= ΔA_{n + 2}-ΔA_n-1 k = (t−t_n) / H k₁= K (1-k) / 4 (11) Where t_n’= (T_n+ T_{n + 1}) / 2, (1
From equation 1), (Equation 20) k = (t_n'-T_n) / H = (t_{n + 1}-T_n) / 2h k₁= K (1-k) / 4 Becomes On the other hand, from the baseline that interpolates the time point t
The quadratic interpolation formula for the difference ΔA (t) is (Equation 21)           ΔA (t) = ΔA_n+ KD_n-K₁(D_{n + 1}-D_n-1) (12) Given by Therefore, at time t_n’
A_n'Is obtained by the equation (12). This difference ΔA_n’Value at time t_nAnd t_{n + 1}
Intermediate time t_n’Is determined by interpolation.
Further, t is given by the equations (11) and (12)._nAnd t_{n + 1}Between
Any number can be obtained. Note that the quadratic interpolation method
We explained about the data processing by using a higher order interpolation method.
Doing so will give a more accurate value, but will take longer to calculate.
You. In addition, data processing by the complement method is performed for all difference data.
Is inefficient because it takes a lot of processing time
The touch beforehand can be detected based on the data before
Touch position (for example, the maximum difference value)
It is sufficient to apply the complement method to the difference data of. To find the touched position by the quadratic interpolation method
Is, for example, as shown in FIG.
The maximum difference directly known from_nThen ΔA_n-1,
ΔA_n, ΔA_{n + 1}, ΔA_{n + 2}Into formulas (11) and (12)
Enter ΔA_n’, And ΔA_n-2, ΔA_n-1, Δ
A_n, ΔA_{n + 1}Into the equations (11) and (12), and t_n-1
And t_nΔA at the intermediate point of time_n-1’. Next, Δ
A_n-1’, ΔA_n, ΔA_n’Touch the largest value
Position. [0065]Example C As described in the problem C, the ultrasonic detection device uses
Since the number of points is large, the data processing time is long,
Slow down. Therefore, data processing after sampling is
The higher the speed, the higher the scanning speed. For example, the width of the finger is 1.
Since it is about 0mm, if you touch panel 1 with your finger
The sampled A / D conversion value is
The part that decreases from the baseline value
Only the width part. Therefore, when the resolution is 0.3 mm,
In this case, 10 / 0.3 = 33 points.
Data processing about 50 points before and after the touched position.
That is enough. For example, when processing under the same conditions as in the example of Task C
When the interval is calculated, it becomes about 0.5 ms.
It will be 1.0 ms. This requires the driving of the A / D converter
Other processing times add up to about 4 ms. Further
In addition, even if noise is smoothed, it takes about 2-3 ms.
The scanning time can be set within about 6 to 7 ms just by adding.
And This scan time is sufficient for tablet operation time
It is a speed that can follow. A 16-bit microprocessor
Scanning time can be further increased by using a processor and a high-speed clock.
Be faster. In the ultrasonic detection device shown in FIG.
The operating flowchart of FIG. 10 illustrates an embodiment of the present invention.
In step S41, the ultrasonic electric signal is displayed.
Sampling time (below, open
And the sampling time at the end of reception (hereinafter referred to as the open price).
End value) is read from the SRAM 21 and the CP
It is stored in the register of U23. In step S42
Reference level value related to the X axis stored in RAM 24
Is written to the CPU 23. Next, proceed to step S43.
Of the sampling data stored in the SRAM 21.
Selected, for example one or two measurement
Sampling data and corresponding measurement sampling data
Baseline data to be read by the CPU 23,
The data of the difference between the data and the
Stored in a register. Next, the process proceeds to step S44,
Minute data exceeds the reference level Ath stored in the register.
At each sampling from the start value to the end value
Is determined for each interval, and the
Set the sampling time to the first time X_LAbove the reference level
Sampling just before it falls below the reference level again
Time to the second time point X_RStored in registers as
Is done. If the difference data exceeds the reference level value
Move to step S45, and turn on Y-axis switches 14 and 16
And steps S41 to S
44 is executed, and the difference data is
Data is determined to exceed the Y-axis reference level value
Determines that there is an object touch on panel 1 (touch-on)
Then, the process moves to step S46. In step S46, the data is stored in the RAM 24.
The set constant C for setting the area is read out and sampled.
Ring time X_LX minus C_L-C is the starting value
And the sampling time X_RTo which C is added X_R+ C ends
It is stored in the register of the CPU 23 as the end value. Stay
In step S47, each measurement sample between the start value and the end value is measured.
All sampling data is read out without being selected,
Each difference data from this and the corresponding baseline data
Is calculated and stored in the register. And each difference data
The maximum difference data from the data, and the sampling time
Is X_MIs stored in the register, and the next step S4
Move to 8. Steps S46 and S4 are similarly performed for the Y axis.
7 is executed. In step S49, the sample
Time X_MX-axis position corresponding to is the X coordinate of touch-on
And the Y coordinate is also specified. Steps
In S50, the CPU 23 sends the
On the other hand, data indicating touch-on along with its coordinate data
Send out. The sampling time and the coordinates are one-to-one.
Therefore, if the setting constant C is about 10, about 50 points
The detailed data processing may be performed on the difference data. In step S44, the difference data is used as a reference.
There was no touch-on if the level value was not exceeded
And without moving to step S45,
And the detection operation of the next measurement sampling data is repeated.
It is. In step S45, the difference with respect to the Y axis
Touch even if minute data does not exceed reference level value
The process proceeds to step S46 assuming that ON has not been detected.
The detection operation is repeated immediately. In steps S41 to S45, the sump
Time series of rings, X₀, X₁, ..., X_nFor X₀,
X₁,..., For example, one interval
And X₀, X_Two, X_Four, ..., or X at intervals of two₀,
X_Three, X₆,…, Read data at predetermined intervals
The above determination operation is performed by_L, X_RSeeking. data
The data processing time is shortened by increasing the reading interval.
The scanning speed can be increased. X
_L, X_RIs determined, the data from the start value to the end value
The data is stored in steps S46 to S50 without an interval.
Data processing is performed. High-speed determination of presence / absence of touch by hardware
Performed, touched period X_L~ X_RKnow first, then
As mentioned earlier, that X_L~ X_RMy data around
Into the microprocessor 26 and decompose only that part in detail.
Data processing may be performed. Figure 11 shows the object panel
Time to quickly detect the presence or absence of touch by hardware
It is an example of a road. FIG. 11 shows the circuit of FIG.
SRAM 51 for storing in, a subtracter 52, a comparator 53,
The timing generator 54 is added. Microphone
The processor 26 includes an SRAM 51, a comparator 53,
The timing generation circuit 54 controls the
Represents an A / D converter 19, a buffer 20, an SPRAM 21,
The operation timing of the subtracter 51 and the subtractor 52 is controlled. FIG.
The signal demodulated by the demodulator 18 of the A / D converter 1
9 is converted to, for example, 8-bit data P,
It is stored in M21. At the same time, this data P is
2 and is also supplied to the buffer 22. one
On the other hand, the baseline sampling data is
51 and the microprocessor 26
Corresponds to the same position as D-converted measurement sampling data P
The sampling data Q of the baseline to be
1 and input to the other end of the subtractor 52. Do
And the subtractor 52 calculates the difference ΔA = Q− between the two inputs P and Q.
P is output to one input terminal of the comparator 53. Data P
And Q are 8-bit data, ΔA is also 8-bit data.
However, a borrow signal may be output.
The other input terminal of the comparator 53 has a microprocessor 2
From 6, a touch-on / off reference value Ath is input.
This Ath is also a digital value, for example, ΔA is 8 bits.
Ath also has 8 bits. Comparator 53
Compare the magnitudes of the two inputs ΔA and Ath, and compare their magnitudes.
Is output. This signal is a microprocessor
26. FIG. 12 is a flowchart of scanning using the circuit of FIG.
Low, and in step S51, the X-axis switch
13 and 15 turn on (Y-axis switches 14 and 16 turn off)
In this state, the detection operation for the X axis is performed, and as shown in FIG.
Circuit and sampled data at the same time
ΔA is calculated, and the reference value Ath is compared with the magnitude.
The result is notified to the microprocessor 26. Difference based
If the threshold is exceeded, the following detailed data processing is executed.
You. In step S52, the
The setting constant C for setting the area to be read is read. Step S
At 53, the highest value stored in the register of the CPU
First sampling time X exceeding reference level Ath
_LAnd after the reference level has been exceeded,
Sampling time X just before_RAnd setting constant C, X_L
X minus C_L-C is the starting value and X_RTo C
X plus_R+ C is the end value and the CPU 23
Is stored in the star. Next, the process proceeds to step S54, where the start value
To the end value are stored in the SRAM 21 and the SRAM 31.
Measurement sampling data and baseline sample
Is read by the CPU 23, and each sampling
Measurement sampling data and
The difference data from the baseline data is calculated and CP
It is stored in the register of U23. Next, in step S55
Move to find the maximum difference data among the difference data and X_MWhen
Then, the process proceeds to the next step S56. Y-axis switch 14, 1
6 is turned on and the difference is calculated in the same way for the Y axis.
And compared with a reference value. If the difference exceeds the reference value
Then, steps S51 to S55 are executed, and the Y-axis supersonic
The maximum difference data is calculated for the wave. Step
In step S57, the sampling time X_MX corresponding to
The position of the axis is specified as the X coordinate of touch-on,
The Y coordinate is also specified. In step S58, the CPU 2
3 indicates touch-on to the host computer 28
The data is sent together with the coordinate data. In step S51, the difference data is used as a reference.
There was no touch-on if the level value was not exceeded
And without moving to step S52,
And the detection operation of the next measurement sampling data is repeated.
It is. In step S56, the difference with respect to the Y axis
Touch even if minute data does not exceed reference level value
The process proceeds to step S57 assuming that ON has not been detected.
The detection operation is repeated immediately. Using the circuit of FIG. 11 and the flow of FIG.
Perform touch detection by a different procedure from the above procedure
Can also. That is, the A / D converted value by the A / D converter 19
Are stored in the SRAM 21 in advance, and all A / D conversions are performed.
Measurement data from the SRAM 21
Data from the SRAM 51 to the base corresponding to the data.
Each of the line data is output, and a subtracter 52, a comparator
53 is larger or smaller than the reference value Ath of the touch presence
Is taken into the microprocessor 26. this
In this case, the data output from the SRAMs 21 and 51 is, for example,
Time X₀It is good to start in order. FIGS. 13 to 18 show the completeness for waterproofing and drip-proofing.
The supersonic sound of the present invention using a bulk acoustic wave having a completely closed structure
3 shows an embodiment of a wave type detection device. Out of bulk acoustic waves
Shear mode acoustic waves are known not to propagate in fluids
I have. Therefore, for example, liquid silicone rubber with low viscosity
Uses a material that does not absorb sound waves as an adhesive for closed structures
Even if the sound wave is not absorbed relatively,
It is possible. FIG. 13 shows the bezel 10 and the glass detection panel.
1 shows a structure in which the liquid 1 is adhered with a liquid silicone rubber 61.
You. The adhesive surface between the bezel 10 and the detection panel 1 is completely waterproof,
Widen until a drip-proof sealed structure can be realized.
Liquid silicone rubber cures at room temperature, so after bonding
There is no risk of spilling. Reflective array 3 is bezel 1
0 on the surface near the outer periphery of the detection panel 1
Can be Silicon rubber 61 has an adhesive force (for example, a double-sided tape).
To prevent peeling,
A supporter 62 is applied to the back of the detection panel 1 to bezel 10
Secure with screws. Supporter 62 on bezel 10
Use a double-sided tape outside of the screw to fix it.
May be. The supporter 62 has some springs (springs).
Anything that works may be used. Supporter 62 is for reinforcement
So just stop at a few places on the detection panel 1
good. FIG. 14 shows a state in which the liquid silicone rubber 61
The structure shown in FIG. 13 for fixing the shell 10 to the detection panel 1 is substantially the same as that shown in FIG.
Is the same, but the bezel is
A spacer 63 between the glass 10 and the glass detection panel 1
It is a structure that existed. First, the spacer 63 is attached to the detection panel 1.
Are bonded with, for example, silicone rubber 61, and then the bezel 1
0 and the spacer 63 are completely sealed with the double-sided tape 64.
You. Similarly to FIG. 13, the adhesive force of the silicone rubber 61 is
Since the supporter 62 is weak, the bezel 10
Reinforced with screws. In FIG.
The ray 3 is provided on the back surface near the outer periphery of the detection panel 1.
However, this is provided on the surface of the detection panel as shown in FIG.
And horizontal space is required in addition to the spacer 63
As the number of detection surfaces decreases, it is necessary to improve this.
You. Make sure that the reflective array 3 is protected by a waterproof and drip-proof structure.
Is the same as in FIG. In the method of bulk acoustic wave,
Touch the surface of the detection panel 1 opposite the reflection array 3 to the touch surface
Can be used as FIG. 15 shows that the spacer 63 is detected as the bezel 10.
With the liquid silicon rubber 61 interposed between the output panels 1
14 is similar to the structure of FIG.
The structure is even stronger. Two spacers
63 on the surface of the glass detection panel 1
After lightly stopping with double-sided tape 65 in advance,
Fill the space between them with liquid silicone rubber 61
The spacer 63 is fixed to the detection panel 1. Use this time
The double-sided tape 65 is for temporary fixing
This does not hinder the touch detection. That
Then, the upper surface of the spacer 63 and the back surface of the bezel 10 are
And fixed with a wide double-sided tape 66 as shown in FIG. FIG.
4, the reflection array 3 is provided on the back surface of the detection panel 1.
And the support panel 62 detects the bezel 10
Fixed to. FIG. 16 shows the spacer 62 and the bezel shown in FIG.
10 is completely waterproof structure than double-sided tape 64.
This is a structure that replaces vibration welding. With the material of the spacer 67
Can be welded by vibration such as acrylic or plastic
Using the material, as shown in the figure, bezel 10 and space
The support 67 is welded by vibration welding. As shown in FIG.
Prepare burr pool 68 in advance when performing vibration welding
And easy to perform vibration welding. Other structures are the same as in FIG.
The same is true. FIG. 17A shows the bezel 10 and the detection panel.
1. Vibration welding of acrylic or plastic is possible
When using a material, bezel 10 and detection panel 1
It is a structure that is welded by contact and vibration welding. The reflection array 3 is
It is provided on the back surface of the outer peripheral portion of the output panel 1. Reflection array
The tip of the bezel 10 is projected so as to cover b3
This is to prevent the reflection array 3 from entering the field of view.
You. As shown in the figure, the vibration welding portion on the surface of the detection panel 1
The position of 69 is more than the position of the reflective array 3 of the detection panel 1.
In the case of the outer peripheral portion, the influence of the sound wave reflection by the welding portion 69 is reduced.
I will not receive it. Normally, vibration welding parts at the four corners of the detection panel 1
The position of 69 is along the ridgeline as shown by the dotted line in FIG.
But bend the four corners as shown by the solid line.
It is better to set it in a raised position. This occurs as shown in FIG.
The distance between the shinko 4 or the receiver 5 and the vibration welding part 69 is
Shock wave of a sound wave emitted from Nobuko 4 or Receiver 5
Is resonated with the reflected wave from the vibration welding portion 69 and wave
In order to keep the distance L above a certain level to avoid disturbing
You. [0080] 【The invention's effect】 [0081] [0082] [0083]The inventionAccording to the subtraction means and the comparison means
High-speed data processing by hardware configuration of stages
The touched position is detected by
Only the data is processed in detail to obtain the touch coordinates.
Fast scanning is possible, equivalent to a tablet
High-speed input becomes possible. [0084]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic overall configuration diagram of an ultrasonic detection device of the present invention. FIG. 2 is a flowchart illustrating a detection operation of the ultrasonic detection device . FIG. 3 is a flowchart illustrating another detection operation of the ultrasonic detection device . FIG. 4 is a diagram showing a panel surface on which ultrasonic waves are propagated and a principle of a detection operation of the ultrasonic detection device of the present invention. FIG. 5 is a diagram illustrating an intensity distribution of a received ultrasonic signal as a change in wavelength. FIG. 6 is a schematic overall configuration diagram of an ultrasonic detection device of the present invention. FIG. 7 is a flowchart illustrating an example of a detection operation of the ultrasonic detection device . FIG. 8 is a diagram illustrating an example of sampling of a received ultrasonic signal. FIG. 9 is a diagram illustrating an interpolation method . FIG. 10 is a flowchart illustrating an example of a detection operation . FIG. 11 is a main part configuration diagram of an embodiment of an ultrasonic detection device of the present invention. FIG. 12 is a flowchart illustrating an embodiment of data scanning . FIG. 13 is a main part configuration diagram of one embodiment showing a waterproof structure of the ultrasonic detection device . FIG. 14 is a main part configuration diagram of one embodiment showing a waterproof structure of the ultrasonic detection device . FIG. 15 is a main part configuration diagram of one embodiment showing a waterproof structure of the ultrasonic detection device . FIG. 16 is a main part configuration diagram of one embodiment showing a waterproof structure of the ultrasonic detection device . FIG. 17 is a sectional view of a main part of an embodiment showing a waterproof structure of the ultrasonic detection device , and a plan view of a detection panel showing a vibration welding position. FIG. 18 is a main part configuration diagram of an embodiment showing a waterproof structure of the ultrasonic detection device . FIG. 19 is a diagram showing a panel surface of an ultrasonic detection device through which ultrasonic waves are propagated. FIG. 20 is a diagram showing a mounting structure of a transmitter for transmitting ultrasonic waves. FIG. 21 is a diagram illustrating a state of a reception signal of an ultrasonic wave that is received by propagating through a panel. FIG. 22 is a diagram showing a time lapse of a voltage of a received ultrasonic signal. FIG. 23 is a view for explaining sampling of a received ultrasonic signal. FIG. 24 is a diagram showing a sampled ultrasonic signal as a reference baseline. FIG. 25 is a diagram showing a difference between measurement sampling data with touch-on and a baseline. FIG. 26 is an overall external view of a liquid crystal display device used for an ultrasonic detection device. FIG. 27 is a main part configuration diagram showing a conventional example of a waterproof structure of an ultrasonic detection device. FIG. 28 is a main part configuration diagram showing a conventional example of a waterproof structure of an ultrasonic detection device. FIG. 29 is a diagram illustrating the reason why a detection malfunction due to noise occurs. FIG. 30 is a diagram for explaining another reason why a detection malfunction due to noise occurs.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G06F 3/03 G06F 3/033-3/037

Claims (1)

(57) [Claims 1] A plurality of ultrasonic waves having different wavelengths are applied to the X
Oscillating means for oscillating in the direction and the Y direction; transmitting control means for performing control for transmitting the wavelengths of different ultrasonic waves transmitted from the transmitting means in a time-division manner; and receiving means for receiving the transmitted ultrasonic waves. And, disposed on the panel on which the transmitted ultrasonic wave propagates at predetermined intervals corresponding to the plurality of different wavelengths, and selectively reflects ultrasonic waves of a predetermined wavelength passing through a detection surface on the panel. Detecting a presence or absence of a touch of an object at a reflection position of a predetermined wavelength by comparing an ultrasonic wave of a predetermined wavelength received from the reception unit with a reference level. Means for detecting the presence or absence or position of an object that absorbs ultrasonic waves propagating on the panel.